Factors Affecting Reactions [Chemistry]
Factors Affecting Reactions I. Factors Affecting Reactions [545]
• Every chemical proceeds at its own rate.
• By changing the conditions of the reaction, the rate of almost any reaction can be modified.
• The rate of a chemical reaction depends upon:
o Temperature
o Concentration
o Particle Size[SA]
o Catalyst
A. Temperature [545]
• Increasing the temperature causes molecules to move faster, so there’s an increased chance of them colliding with each other and reacting.
• Increasing the temperature also increases the average kinetic energy of the molecules
• Lowering the temperature slows down the reactions.
B. Concentration [545]
• Increasing the number of collisions speeds up the reaction rate. The more reactant molecules there are colliding, the faster the reaction will be
• Putting more particles into a fixed volume increases the concentration of reactants and the frequency of collision.
• Increased collision frequency leads to a higher reaction rate.
C. Particle Size [546]
• The total Surface Area [SA] of a solid or liquid reactant affects the reaction rate.
• Reaction depends on collisions. The more SA on which collisions can occur, the faster the reaction.
• The smaller the particle size, the larger is the SA for a given mass of particles.
• An increase in SA increases the amount of the reactant exposed for reaction which increases the reaction rate.
D. Catalysts [546-547]
• Catalysts are substances that increase the reaction rate without themselves being changed at the end of the reaction.
• They increase the reaction rate by lowering the activation energy for the reaction.
• An Inhibitor is a substance that interferes with the action of a catalyst [Decreases reaction].
• Thus the Inhibitor reduces the amount of functional catalyst available [Its poison to Catalyst]
• Reactions
• Every chemical proceeds at its own rate.
• By changing the conditions of the reaction, the rate of almost any reaction can be modified.
• The rate of a chemical reaction depends upon:
o Temperature
o Concentration
o Particle Size[SA]
o Catalyst
A. Temperature [545]
• Increasing the temperature causes molecules to move faster, so there’s an increased chance of them colliding with each other and reacting.
• Increasing the temperature also increases the average kinetic energy of the molecules
• Lowering the temperature slows down the reactions.
B. Concentration [545]
• Increasing the number of collisions speeds up the reaction rate. The more reactant molecules there are colliding, the faster the reaction will be
• Putting more particles into a fixed volume increases the concentration of reactants and the frequency of collision.
• Increased collision frequency leads to a higher reaction rate.
C. Particle Size [546]
• The total Surface Area [SA] of a solid or liquid reactant affects the reaction rate.
• Reaction depends on collisions. The more SA on which collisions can occur, the faster the reaction.
• The smaller the particle size, the larger is the SA for a given mass of particles.
• An increase in SA increases the amount of the reactant exposed for reaction which increases the reaction rate.
D. Catalysts [546-547]
• Catalysts are substances that increase the reaction rate without themselves being changed at the end of the reaction.
• They increase the reaction rate by lowering the activation energy for the reaction.
• An Inhibitor is a substance that interferes with the action of a catalyst [Decreases reaction].
• Thus the Inhibitor reduces the amount of functional catalyst available [Its poison to Catalyst]
• Reactions